I'm trying to do a mod where your maximum experience is no more than 12 (like I think that in my opinion should be). But I also want to throw down all XP gained for killing foes, and only modify that gained for completing quests. Does anybody knows how to achieve that?

Also: I asked a few weeks ago if there's a way to add new feats. The answer was no, but there was something close to it. I want to know what is that the closest thing that there's to adding a new feat. And in anycase where is the script that describes the effects related to the feats, and the scripts of the effects themselves. Thanks.